diff --git a/g0rnn/README.md b/g0rnn/README.md
index 9529a76..478f27f 100644
--- a/g0rnn/README.md
+++ b/g0rnn/README.md
@@ -32,5 +32,6 @@
 | 28차시 | 2025.06.27 | BFS | [상어 중학교](https://www.acmicpc.net/problem/21609) | https://github.com/AlgoLeadMe/AlgoLeadMe-12/pull/115 |
 | 29차시 | 2025.07.22 | combination | [소문난 칠공주](https://www.acmicpc.net/problem/1941) | https://github.com/AlgoLeadMe/AlgoLeadMe-12/pull/119 |
 | 30차시 | 2025.07.28 | segment-tree | [커피숍2](https://www.acmicpc.net/problem/1275) | https://github.com/AlgoLeadMe/AlgoLeadMe-12/pull/121 |
+| 31차시 | 2025.08.03 | segment-tree | [음주코딩](https://www.acmicpc.net/problem/5676) | https://github.com/AlgoLeadMe/AlgoLeadMe-12/pull/127 |
 
 ---
diff --git a/g0rnn/segment-tree/31-g0rnn.py b/g0rnn/segment-tree/31-g0rnn.py
new file mode 100644
index 0000000..bae7249
--- /dev/null
+++ b/g0rnn/segment-tree/31-g0rnn.py
@@ -0,0 +1,71 @@
+import sys
+input = sys.stdin.readline
+
+def minimize(x):
+    if x > 0:
+        return 1
+    elif x < 0:
+        return -1
+    else:
+        return 0
+
+def build(node, s, e):
+    if s == e:
+        tree[node] = minimize(nums[s])
+        return
+    
+    mid = (s + e) // 2
+    build(node * 2, s, mid)
+    build(node * 2 + 1, mid + 1, e)
+    tree[node] = tree[node * 2] * tree[node * 2 + 1]
+
+def update(node, s, e, i, v):
+    if s == e:
+        tree[node] = minimize(v)
+        return
+    
+    mid = (s + e) // 2
+    if mid < i:
+        update(node*2 + 1, mid + 1, e, i, v)
+    else:
+        update(node*2, s, mid, i, v)
+
+    tree[node] = tree[node * 2] * tree[node * 2 + 1]
+
+def query(node, s, e, i, j):
+    if j < s or e < i:
+        return 1
+    if i <= s and e <= j:
+        return tree[node]
+    
+    mid = (s + e) // 2
+    left = query(node*2,s, mid, i, j)
+    right = query(node*2 + 1, mid + 1, e, i, j)
+    return left * right
+
+while True:
+    try:
+        n, k = map(int, input().split())
+        nums = list(map(int, input().split()))
+        tree = [0] * (4 * n)
+
+        build(1, 0, n - 1)
+
+        output = []
+        for _ in range(k):
+            cmd, i, v = input().split()
+            i = int(i)
+            v = int(v)
+            if cmd == 'C':
+                update(1, 0, n-1, i - 1, v)
+            elif cmd == 'P':
+                result = query(1, 0, n-1, i - 1, v - 1)
+                if result > 0:
+                    output.append('+')
+                elif result < 0:
+                    output.append('-')
+                else:
+                    output.append('0')
+        print(''.join(output))
+    except:
+        break